Controlling device



` Jan. 13, 1931. I G A KNAAK 1 1,788,678

CONTROLLING DEVICE Filed Sept. 2, 1924 A TTORNE 59 tur'es through these lugs being designated by Patenie -Jaa' `13; 1931-" UNITED TATES PATENT; oni-*Ice GEORGE. A. KNAAK, or' MILWAUKEE, Vwrscoivsrrr AssIGNoR, BY Mnsnn Assreivmnn'rs, 'ro PENN, ELECTRIC swn'on co., o r' Dns Momns, 1owA',A coaronA'rIoN 'or Iowa coN'rnoLLING D'EVIGE Application -filed September 2, 1924. Serial No, 735,529.

This invention relates to controlling devices, and the object of the invention 'is to improve the construction and operation of controlling devices in the manner to be hereinafter described and claimed.

Referring to the drawings, which accompany this specification and form a part hereof, which drawings illustrate an embodiment of this invention, and on which drawings the 50 same reference characters are used to designate the same parts wherever they mayappear in each of the several views, Fig. '1 is 'a front elevationi of a controlling device; fFig. 2 is a sect-ion taken on'the line 2-2 on Fig. 1, looking in the directi'on'indicated .by `the arrows; and Fig. 3 is a planiview' of parts of the controlling device taken fon the.

line 3-3 on Fig. 2, looking in the direction indicated by the arrows. w

The principal object of my `invention is. to produce a controlling device, for electric current, which will automatically effect such varlations in an electric current, whether'the' electric current be the so-called direct cursome electrical apparatus which is adapted to be operated, or actuated, by the electric The underlying principleof myV invention is the utilization of the known properties of carbon,'and-possibly-some other material or.

materials withr which Iam not now acquainted, to ofier'lessiresistance to the passage of a so-called' electric current when pressure is applied thereto i My inventlon 1s capable of wide useunder various conditions and may be embodied Vin many specifio forms of apparatus, as will be 'readily understood from the following` description of the construction and operation of a type of apparatuswhich 'is quite p :generally known as a thermostatf Referrin tovv the draWi-ngs, the reference numeral 1 esignates a support which is pro- 'vided with apertured lugs 2 and 3, the aperrent or the so-called alternating current, that the reference numerals 4 and 5 and being I shown bv the drawings as concentric with p each other'though differing in size. The support 1 should preferably be made as rigid as possible to `retain parts in fi'xed positions of adjutment and, for this purpose, the support 1 isillustrated as provided with an in-' tegraland continuous -flange 6 onwhat may be termed the back side thereof and the space 7 provided by-this lange 6 alfords a convenient place for attaching electric 1,,,wires, not shown, to the thermostat and concealing them from view. The thermostat may be attached to a,-wall 8, or other support,

by screws, not shown,'passed through screw holes 9,10,11, and 12 in the support 1.' The .aperture 5 in the lug 3 is screwthreaded .to lreceive the screwthreaded end of a support member 13. This support 'member 13 may be'made from any suitable material and in any suitable manner. The drawings show it as a steel ,tube whichis Screwthreaded on the outside at one end and which'isI screwtlirea-dedon the inside at its other endand it isshown a`s provided'with air passages or draftV holes 14: which are arranged in series, some 'of which are arranged in -serles' `15 circularly around ,the lower end of, the support'member 13 and someyof which arearranged in series 16 circularly around the upper end offthe support member 13,S

as clearly shownl by the drawings.

.The thermostat is shown as provided with asplurality 'of carbon members 17 whichare illustrated bythe drawinj'gs` as 'disks withV lholes through-'their Centers, this specific'construction being adopted merely as a matter of convenience in constructing and assembling the thermostat and for the security of the 'thermostatbafter its parts have been assembled. .The llowermost of` these carbon members rests vupon a fixed abutment or unyieldable member whichis illustratedby the drawings as a metal disk 18, so as to provide Jan electrical connection between theimetal disk 18 and the"lowermost carbon member andthe severalcarbon membersare in contact to provide an electrical connection between them. The metal disk 18 is shown by the drawings as secured to a bolt 19 whichis provided with a shoulder and a nut 21 on its upper screwthreaded end] The bolt 19 passes through the aperture 4 in lug 2 but is insul-ated from the lug 2 by insulating material 22 and insulating material 23 is applied between the lug 2 and the-nut 21, and insulating material 24 is also ,applied between the lug 2 and the shoulder 20 'on the bolt 19. In-

s'ulating material 25 is'also applied around the bolt 19 between the shoulder20 andV the metal disk 18 and extends through theapertures in the carbon members 17. A conductor terminal 26 may be placed in electrical connection with the bolt 19,'metal disk 18,

and the carbon members 17 by being clamped between the nut 21 and the insulating material 23. A pressure member, which is preferably some suitable kind of` resilient or yieldable means and which isillustrated by the drawings as a spiral spring 27, is shown as interpos'ed between an insulating washer 28 and a. connection terminal 29 which is in metallic contact with an inverted metallic cup 30. The metallic cup .30 may be'provided with air passages or draft holes 31, and it' will be readily understood from theconstruction so far described, that the carbon mem-.

bers ,17 are pressed together by'the power 'ezerted by the spiral spring 27, thereby resenting less resistance to thepassag'e o an electric current, than if the carbon members 17 were not pressed together. It will be understood, of course, that the metallic cup 30 serves to make an electrical connection between the terminal 29 and the carbon-members 17, metallic disk 18, bolt 19, and conduc-' tor terminal 26, but it also serves'as a pressure "diminishing member for diminishing the pressure, to which the'carbon members 17 are subjected, in the mannernto be now described.

, The metallic cup 30, as'shown' by ,the drawg disk 18 to accommodate the predetermined ings, projects suficiently beyond the metallic possible movem'ent of a release device 32. The release device 32 is illustrated by the drawings as a hardA rubber tube which rests against a flange plate 33 and'enters at its other end and abuts' against the bottom 34 of a depression 35 in a plate 36 which is provided with a flange 37 inside of lwhich the open end ofthe metallic cup '30 is assembled. The flange plate 33 is provided with an aperture 38 through which extends a pin 39. The pin is illustrated by the drawings as integral with a screwthreaded stem 40, formed with j head 41., and this construction provides a support 13 and the shoulder 44 and is pro-l vided with Igraduation marks, for example, to indicate degrees of temperature. Ashell cup 47 is secured to the head 41 by a screw 4,8, as a simple mechanicalexpedient 'for giving a well finished'appearance to the thermostat,

and a cup 49 is .pressed into the top of the' ,shell' cup 47 and is provided with a projectingpomter 50 to be observed in connection with 'the graduations on the dial plate 46. In

'order'to permit the airlto circulate within the release device or hard rubber tube 32, draft holes 51 may be provided in the plug 43, d/raft holes 52 may beprovided in the flanged plate' 33, and one ormore draftholes 53 may be provided in the plate 36 to 'communicate withthe bore 54 ofthe release device or hard rubber tube 32. The function of the several draft'holes, referred to, issimply toV permit a free' circulation of air in contact with thev inside and the outside of the hard rubber tube, or releasedevice, 32 so that thefrele'ase device 32 will be readily responsivefto varia-7 tions in temperatures. draft holes 31 inthe metallic cup 30 are to provide for free circulation of air to dissipate The air passagesf'or the heat which maybe generated in the carbon members 17 when the passagefof electric current is beingresisted what may be ermed low pressures upon the carbon'memers. The principle of construction and operation of'thecontrolling device will be readily understood from the foregoing description and the following `explanation. As before stated, the principle of the operation of the controlling 'device consists in producing a variable electric current or a variationin an electric 'current vby resistance mechanism which is'subject to change in its total resistancefiThe invention may be embodied in different. forms and constructions of apparatus without, -however, departing from the principle of operation of my invention. The specific construction of controlling device illustrated by the drawings 'will operate to increase resistance to the passage of an electric current either by an increase in temperature or by a decrease in'temperature ac-' cording to the initial setting or adjusting` of the device. Assuming that the controlling device vis .set to shut ofl1 or decrease the supply of heat lwhenthe temperature of a room, for example, has reached 70 degrees the re-' lease device, or hard rubber tube 32, which expands, with a rise of temperature, more T30 against the plate '36 and lifted the metallic 'than the support member 13, has 'pressed j cup 30 against the tension of the Vpressure lin On a lowering of the room temperature, the contraction of the release device (rr hard rubber tube 32 is greater than the contraction of the support member 13, With the result that'the pressure member or spiral spring?? can exert greater pressure upon the carbon members 17 thereby diminishing the resistance to the passag'e. of electric current.

By adjusting the releasedevice 32 to a higher position, it Will be readily seen that the initi'al resistance of the carbon members 13 `to the flow. of electric current 'is high and that theresistance is reduced as the temperature falls. vlltewill also be readily understood that the popsitions of the pressure memher or spiral' spring 27 and the release 'depi vice 32 can be transposed Without afecting the principle of the construction and operation of the controlling device as it is only necessarypto have a pressure member. and a release device to increase or diminish the resistance of the carbon members 17. ,V

`While it is not necessary or desirable to have extreme movements take -place so that Q there Will be an actual breaking of the other- Wise continuous electric Circuit, the. lowermost carbon member v1'? may be cemented or otherwise secured to the metal disk 18 and the 'uppermost carbonmember 177 may be cemented orotherwise secured to the metallic cup '30, so that 'ifthe range of movement of.

the metallic cup with respect to the metal disk 18 was sufficient to cause actual separation of members, the separation Would be between carbon members and not between a metallic member and a carbon member. The reason for this is that if, for example, the metallic cup 30 Were'to be. separated from the uppermost carbon member 17, there might be a slight arcing which Would tend to roughen the metal surface and prevent good contact again While such a result Would not occur as the result ofthe same amount of arcing between carbonmembers.

The cup 49 is provided with a'plurality of opertures 'and a pin'V 56, which extends through a hole 57 in thel head" 41,- may be engaged in anyone of the' several'holes 55 I so that the pointer 50 will closely approximate the graduation on the dial platet alt which lthe controlling device will efiect a .su-flicient Variation in the electric current to perform the function desired. By unscrewing' the screw48 the Shell cup a? and. the cup 49 can be dropped suficiently to disengage the ,p pin 56 from one bf the apertlies 55 to engage the pin 56 With another f said apertures, in am'anner which will be-ireadily understood, and the screW 48 can 'then be screwed back to'retain the Shell 'cup 47 and the cup 49 in proper assembled relation With i the head A411.,

The reference numeral 58 designates ia binding post fora Wire to aford an electrical' connectionthrough the Wire 59 to the conductor or connection terminal 29, and the reference numeral 60 designates a binding post fora Wire to afi'ord an electrical connection through the Wire 61'to the conductor or connection terminal '26. i i

It will be understood, of course, that the adjustment ofthe thermostat or-the setting of it to operate at a predetermined temperature is obtained by:` rotating the head 41 to move the release device 32 towards' or away' from the plate 18 and that the adjustment of the pointer 50 to correspond With the graduaxtion'at'which the thermostat is set to operatev which are passed through the screW holes 9 and 10 and through the holes for the binding posts 58 and 60. The eyelets which pass ,through the screw holes 9 and 10 require no insulation, but the binding posts 58 and 60 areV p operly w, insulated from the eyelets throughwhich they pass.. The metal eyelets ins'ulating' material 63 and 611' to .serve as,

x66 and 'imerely pass ,through the strips of lbushings for the holes 68 and 69 'through 5 which thev connecting wires are passed from the back to be attached to the binding posts 58 and 60. Large holes 70 and 71 are provided in the support 1 for the passage of suchwires; The drawings show the insulation 62as secured by the metal eyelets 85..

'The great objection to .the existing controlling devices is that they are of a make and break type and are unreliable at the time of making and breaking contact due to jars' and vibrations of buildings or structures where they are mounted. My invention overcomes the unreliability and uncertainty of existing controlling devices by rendering' the action of the device positive and reliable.

What ll claim is:v v1.. The combination in a controllingv device, ofa 'support provided with lugs, the

said lugs being provided with apertures in line with each other, a metallc plate secured to one of said lugs but insulated ther'efrom,

a plurality of'carbon .disks forming a pile which rests against saidmetallic plate, a metal-lie cup resting 'against the opposite end of the pile of carbon'disks, a conductor terminal- .in electrical connection-With said I metallic plate, a conduotor terminal 'in electrical connection With 'said metallic cup, a

spring tending to force 'said metallic cup to; Wards said metallic plate to apply pressure A to said'carbon disks, a support member, and w 'a release' device adapted to move said metallic cup in opposition to the tension ofsaid spring to dimimsh pressure exerted by said sprmg upon the said carbon disks.

2. The combination in a controlling de- 5 vice, of a-support, a 111g thereon, .a metallic platel suspended from saidlug, a plurality of carbon disksforming'a pile which rests 'on 'and against said metallic plate, a metallic contact member of inverted' cup-sha e resting on and against the opposite en of the pile of carbon disks, means for providing electrical connections to said metallic plate'n and said metallic contact member, a spring tending to force said metallic contact memw ber'toward said metallic plate to apply pressure to said carbon disks, anda release device arranged to exert pressure against the rim of said metallic contact member and to move it vin opposi'tion 'to said spring to .diminish the lpressure exerted by said spring upon Ithe i carbon disks.

In witness whereof hereto Aaifix my signature. i). I

GEORGE A. KNAK. 

